Improvement in steam safety-valves



ALBERT e'. Blitzer, 0F PHILADELPHM. PENNSYLVANIA.

Leners Panni-N0. 76,992, me April 21, 1.868.

IMPRUVEMENTIN STEAM sArsT-YfVALvss.

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.TO ALLWHOM IT MAY GONGERN: p i

Be it known that I, ALBERT G. BUZBY, of Philadelphia, county ofPhiladelphia, State of Pennsylvania,

lhave invented a Duplex Safety-Valve for Boilers; and I do herebydeclare the following to be a full, clear, end

exact description of the same.

My invention consists o f two valves,one being connected to but lo'adedindependentlyofthe other valve, the two valvesV being contained within acasing, so thatv if the"lever of one valve should be tampered with, 'orfail to perform its functions, the other valve remains in 'aninaccessible position, to relieve the'boiler. from surplus'steam.

In order to enable others skilled in tnc art to make and applymyinvention, I willnow proceed to'describe its construction, andoperation, reference heilig had to the accompanying drawing, whichyforms a part of this specification, and in which- Figure 1 is a verticalsection of my improved safetyvalve.

Figure 2, a'scction on the line 1-2, fig. 1.

Figure 3, a plan view, with a portion of the case removed.

Similar letters refer to similar parts throughout the several views.-

A is the lower, and A the upper portion of a valve-chestV or case, thelower portion being secured to a steam-boiler, and having two openings,a and a', communicating with the interior. of the boiler.l At the upperedge of the opening d is formed a seat for the valve B, and at the upperedge of the opening a', a. seat forthe valve B. l

To a graduated and weighted lever, D, is jointed alink or rod, d, thelower end of which is connected to or rests on the valve B', and a link,e, serves to connect the same lever tothe valve B, 'on which isa.cross-bar,

f, the latter being arranged to slide vertically on rods z'z', securedbelow the valve-chest, and provided at thetop with nuts, jj,betweenwhichand the said cross-barf, intervenevspiral springs coiled around therods z' z'.

The lever Dis loaded as usual, so'that the'valve B will not be elevateduntil the steam within the boiler exceeds a given pressure, when 'thelever will be raised, its fulcrum-.being the 'pin to which thc, link eof the valve B is connected. y I

The springsor thc appliances-for-loading thcvalve B, are such that thelatter is depressed with a force slightly inexcess of that exerted onthe valve B', so that under ordinary circumstances the valve will remainstationary, while the valve B will perform-its duty of permitting auexcess'v of steam to escape. Should-a dangerous excess of steam besuddenly generated, howeveigfboth valves` will be elevated, andl thev.boiler will bo quickly relieved.' The main object ofthe invention,however, is to prevent any tampering with the valves,

which arecovered by a casing, A', soconstructed as to permit the freeescape of the steam, but sp las to prevent access to' the alve B, theupper portion of the casing being suitably locked t the lower casing.

Should'tlie lever D, which projects 'througha slot in the upper portioncf the casing, be over-.weighted or held down, the valvel B, to whichready access'cannot be had, remains to perform its duty, which it willdo independently of the lever, as it has an independentload.

I claim as my invention, and'desire to secure by Letters Patent- The twovalves, B and B', the former being connected to but loadedfindependeutlyol' the valve B, when thc said valves are contained within a casing,substantially as and for the purpose herein' set forth.-

In testimony whereof, I havesigned my name to this specicationin thepresence of two subscribing witnesses.

A. G. BUZBY.

Witnesses JOHN. WHITE, W. J'.- Rf DnLAnr.

